Dissociation of duodenogastric marker reflux and bile salt reflux

Duodenogastric reflux of a perfused marker and bile salt reflux, as well as emptying of fasting gastric contents and gastric secretion, were measured simultaneously in six healthy volunteers. Each of the subjects was studied three times in randomized order during intravenous administration of either saline or atropine (40 micrograms/kg/4 hr) or cerulein (360 ng/kg/4 hr). Fractional gastric emptying rate was inhibited from 4.57%/min +/- 0.50 SE to 0.70 +/- 0.15 by atropine (P less than 0.001) and to 1.80 +/- 0.29 by cerulein (P less than 0.005). Atropine increased reflux of duodenally perfused phenol red from 0.95 +/- 0.28 to 26.09 +/- 4.98% (P less than 0.005) without affecting bile salt reflux (0.44 +/- 0.07 vs 0.51 +/- 0.17 mumol/min). In contrast, cerulein did not significantly affect duodenogastric marker reflux (2.23 +/- 0.82%) but increased bile salt reflux to 0.94 +/- 0.16 mumol/min (P less than 0.05). It is concluded that reflux of duodenal contents and reflux of bile salts do not necessarily parallel each other. This may produce considerable confusion by apparently contradictory results in studies on duodenogastric reflux.